INDUCTION OF FLOWERING IN CABBAGE PLANTS BY IN VITRO VERNALIZATION, GIBBERELLIC ACID TREATMENT AND RATOONING

Abstract

A study was carried out to determine whether applying cold to plants in vitro, or gibberellic acid treatment later to green plants in soil, alone or in combination, can induce flowering in cabbage plants raised from seeds at 20°C. Sterilized seeds of four lines of cabbage were cultured in glass jars and kept in the growth room 25°C for 56 d after which they were cold treated (6°-1 3°C) for another 56 d. The seedlings generated were later transplanted into 15 cm-plastic pots and 250 mg 14gibberellic acid (GA) was later applied to the leaves of plants, followed by six further applications at 1-week intervals. Results showed that one line, '11R1 003202 produced more leaves than the other three lines but the stem girth of the lines was not affected after 8 weeks cold treatment. At 21 d after transplanting, 1-R1003202 ' had the smallest stem girth, shortest leaves and stem and highest leaf number however all lines varied significantly from each other in terms of stem height. For line `HRI 006556', GA, did not have any effect (P > 0.05) on cold treated plants but reduced both the leaf number and number of days at flowering of the control plants. One of the three replicates of line 'HRT 007617 ' flowered when a combination of cold and GA ,treatments was applied to plants.